all astrovan discs will not work. i tried 2 different ones. at least when trying to go behind a 235/261 with stock bh. i tried this & the hub in the clutch disc would not let the trans. go all the way up to the mount surface on the bh. if i remember correctly it was a 1/4". that's when i came up with the vega clutch hub swap. check the tech section. there's alink to it in jacks' article. some have suggested grinding down the astrovan hub. it looked a little short to me as it was so i was unwilling to do that. what i wrote was based on the best info. i had at the time. some have suggested the vega hub swapped into the larger disc isn't worth the cost. personal choice i guess. altho it may be cheaper with a different rebuilder than the one i used. if i had it to do over again i'd check out the clutch disc for v6 camaro. another thing i've since learned is the 14 spline input shaft & bearing collar for the nwc v6 camaro trannies is the same length as the older gm trans. & doesn't have to be shortened.
better yet is to stay with the 26 spline/2.95 1st gear v8 camaro version & s10 tailhousing like i've put together for my '50 coupe. better ratios and a little higher torque rating and readily available bolt in clutch. when i wrote the article i hadn't discovered ebay yet where these trans. go for 3-500 $$ all the time.
robert